code: def test_error_if_exp_value_not_allowed():
      with pytest.raises(ValueError):
          PowerTransformer(exp="other")
  
file_path: feature_engine/tests/test_transformation/test_power_transformer.py
imports: import pandas
  import pytest
  from sklearn.exceptions import NotFittedError
  from feature_engine.transformation import PowerTransformer
label_desc: Use image node_id 2 for calling a global function with example usage: test_error_if_exp_value_not_allowed() without return types